1.1 ,This specification covers the general requirements for protective zinc coatings (hereinafter referred to as the coatings) to be applied by the thermo-diffusion coating (TDC) method, to various products made of carbon steel, including low and high tensile parts as well as of wrought iron, iron and steel castings, sintered iron steel-powder, and various steel and stainless alloys. TDC is a dry coating process carried out by immersing the parts in a zinc or zinc alloy powder at elevated temperature for a period of time, causing a metallurgical diffusion process of zinc and iron. Further processing may be added, such as passivation, topcoat application, paint application, etc.